This book offers the first English translation of the Quodlibetal Questions of William of Ockham (c. 1285-1347)--reflections on a variety of topics in logic, ontology, natural philosophy, philosophical psychology, moral theory, and theology by one of the preeminent thinkers of the Middle Ages. It is based on the recent critical edition of Ockham's theological and philosophical works.The Quodlibetal Questions inaugurates the Yale Library of Medieval Philosophy, a series that will make important philosophical works of the Middle Ages available in accurate English translations.